1. Field of the Invention
The present invention is related to a vehicle travel safety apparatus for avoiding contact with a object based on the relationship of the relative positions of a vehicle detected ahead of the subject vehicle by a object detection apparatus such as a laser radar.
2. Description of Related Art
Conventionally, as disclosed in Japanese Unexamined Patent Application, First Publication, No. Hei 8-240660 and Japanese Unexamined Patent Application, First Publication, No. Hei 6-160510, for example, a vehicle travel safety apparatus is known in which electromagnetic radiation such as a laser is emitted towards a vehicle traveling forward ahead of the subject vehicle, and based on the result or the detection of the radar that receives the reflected wave from the object of the vehicle and the like positioned in front of the subject vehicle, detects an obstacle traveling forward in front of the subject vehicle, and based on the result of this detection generates an warning that brings about, for example, an avoidance operation by the driver based on the results of this detection, or automatically carries out a controlling action to avoid contact with the obstacle.
In addition, among a travel safety apparatus of this type, apparatuses are known that carry out the operation of warning about a collision avoidance taking into account the speed of the subject vehicle, the path of the subject vehicle, the relative distance from the obstacle, the relative speeds, the relative angles and the like.
However, in the conventional vehicle travel safety apparatus, it cannot always be said that the elements of the condition of the driver are sufficiently reflected in the operation control of the travel safety apparatus, and thus, actually, there are cases in which warnings and collision avoidance control are carried out even in a situation where the driver is steering in advance to avoid an obstacle such as a vehicle in front. Thereby, the operation * of the travel safety apparatus may be complicated for the driver, and unnecessary avoidance actions may occur for an obstacle that presents no danger, thus inviting deterioration of the drivability.
For example, a situation in which a driver is momentarily distracted for about one .second for a safety check or speed check can certainly occur during normal driving, and in this type of situation, there are many times that the vehicle is traveling almost perfectly straight. In addition, at this time, the steering angle operated by the driver is small, the change of the steering angle is low, and the transversal acceleration of the vehicle is low. In such a situation, when the vehicle travel safety apparatus determines that the collision danger is high, preferably warnings and collision avoidance control is rapidly executed.
In contrast, when a steering operation is carried out that is of a degree for cornering the vehicle or changing lanes, etc., generally because the driver is driving while paying sufficient attention, and thus in this situation when warnings and collision avoidance control is carried out by the vehicle travel safety apparatus at the same timing as in the situation of the momentary distraction mentioned above, not only is this complicated for the driver, but there may be a sense that the drivability has deteriorated.
In consideration of the conventional problems described above, it is an object of the present invention to provide a vehicle travel safety apparatus that can improve drivability by modifying the avoidance action timing when the turning of the vehicle is detected.
In consideration of the above problems, in a first aspect of the present invention in it is an object of the present invention to provide a vehicle travel safety apparatus (for example, the travel safety apparatus 10 in the embodiment described below) providing a object detecting device (for example, the radar apparatus S1 in the present embodiment described below) that detects a object in front of the subject vehicle (for example, the forward moving vehicle V11 in the embodiment described below), a relative velocity calculating device (for example, the radar apparatus S1 in the embodiment described below) that finds the relative velocity between the subject vehicle (for example, the subject vehicle V10 in the embodiment described below) based on the result of the detection of the object detecting device, a contact possibility estimating device (for example, the action timing determining part 22 in the embodiment described below) that estimates the possibility that the object and the subject vehicle will come into contact based on the result of the calculation of the relative velocity calculating device, and a contact avoidance support device (for example, the brake actuator 12 and the warning apparatus 17 in the embodiment described below) that automatically acts in a predetermined interval before contact when it is estimated that there is the possibility of contact by the contact possibility estimation device, and supports contact avoidance between the object and the subject vehicle, wherein a turning state detecting device (for example, the yaw rate sensor S3, the transversal acceleration sensor S4, and the steering angle sensor S5 in the embodiment described above) that detects the turning state of the subject vehicle, and a compensating device (for example, the steps S1 to S11 in the embodiment described below) that compensates the predetermined interval when a turning state of the subject vehicle is detected by the turning state detecting device.
Due to this type of structure, when it is estimated that there is the possibility that the subject vehicle may contact a object such as a vehicle in front and when the turning state of the subject vehicle is detected, the action timing of the contact avoidance support device can be compensated, and action control of the travel safety apparatus taking into account the elements of the state of the driver is possible.
In addition, according to a second aspect of the invention, in the invention according to the first aspect, the compensation device is characterized in slowing the predetermined interval. Due to this type of structure, when turning state is detected, the action of the contact avoidance support device can be made slower than when a turning state is not detected.
In addition, according to a third aspect of the invention, in the invention according to the first and second aspects, the turning state detecting device is characterized in detecting the steering angle due to the operation of the driver. Due to this type of structure, compensating the predetermined interval described above depending on the size of the amount of the steering angle is possible.
In addition, according to a fourth aspect of the invention, in the invention according to any of the first through third aspects, the turning state detecting device is characterized in detecting the changing rate of the steering angle due to the operation of the driver. Due to this type of structure, in the case that the steering angle and the changing rate of the steering angle are both detected by the turning state detection device, the detection of the turning state can be carried out more precisely and the compensation of the action timing of the contact avoidance support device can be more precise.
In addition, according to a fifth aspect of the invention, in the invention according to any of the first through fourth aspects, the turning state detecting device is characterized in detecting the transversal acceleration of the subject vehicle. Due to having this type of structure, in the case that the transversal acceleration and the steering angle or the transversal acceleration and the changing rate of the steering angle velocity, or the transversal acceleration and the steering angle and the changing rate of the steering angle are detected by the turning state detection device, the detection of the turning state can be more precise and the action timing of the contact avoidance support device can be more precisely compensated.
In addition, according to a sixth aspect of the invention, in the invention according to the first and second aspects, the turning state detecting device is characterized in detecting at least two among the steering angle, the changing rate of the steering angle, and the transversal acceleration of the subject vehicle, and compensates the predetermined interval by selecting the largest among the plurality of compensation amounts found by the turning state detecting device. Due to having this type of structure, the turning state can be detected more precisely and the action timing of the contact avoidance support device can be compensated more precisely.
In addition, according to a seventh aspect of the invention, in the invention according to any of the first through sixth aspects, the contact avoidance support device is characterized in being a vehicle control system. Due to having this type of structure, contact avoidance can be reliably carried out without depending on the operations of the driver.
In addition, according to an eighth aspect of the invention, in the invention according to any of the first through seventh aspects, the contact avoidance support device is a notification device provided in the vehicle. Due to having this type of structure, the attention of the driver can be alerted so that he or she will carry out the procedures for contact avoidance.